1. Field of the Invention
Apparatuses and methods consistent the present invention relate to image quality improvement, and more particularly, to removing artifacts generated when a luminance signal and a chrominance signal are not clearly separated to thereby improve image quality.
2. Description of the Related Art
A composite video signal includes a luminance (Y) signal and a chrominance (C) signal that are modulated within a restricted bandwidth and inputted to an image processing device. Most image processing devices developed in recent years are equipped with a comb filter by which the composite video signal is separated into luminance and chrominance signals and decoded to be restored to an image.
FIG. 1 is a block diagram of a comb filter employed in a related art image processing device for improvement of image quality.
Referring to FIG. 1, the comb filter 10 includes a BSF (Band Stop Filter) 12 and a BPF (Band Pass Filter) 14.
BSF 12 is a filter for eliminating or stopping the interference of a specified band of frequencies. For instance, C signals are filtered out by the BSF 12 and only Y signals are outputted. On the other hand, BPF 14 is a filter that allows only a specified band of frequencies to pass. For instance, only C signals are outputted through the BPF 14.
As the Y signals and C signals are separately outputted from each other by the comb filter 10 with the above configuration, interference between Y and C signals is removed to thereby improve image quality.
In separation of Y and C signals, however, some of the interference is not completely removed depending on the performance of the comb filter 10, and the separation of Y and C signals can be difficult if a high degree of motion is detected in an image. In such case, artifacts such as “dot crawl” or “cross color” appear along the edge of a vertical line, thereby degrading image quality.